Gotweb

Blob

Date:: Wed Oct 13 18:48:15 2021 UTC
Message:: fix two more error strings in pack_create.c using the wrong function name
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2020 Ori Bernstein
3  * Copyright (c) 2021 Stefan Sperling <stsp@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/uio.h>
22 #include <sys/stat.h>
23 
24 #include <stdint.h>
25 #include <imsg.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sha1.h>
30 #include <limits.h>
31 #include <zlib.h>
32 
33 #include "got_error.h"
34 #include "got_cancel.h"
35 #include "got_object.h"
36 #include "got_path.h"
37 #include "got_reference.h"
38 #include "got_repository_admin.h"
39 
40 #include "got_lib_deltify.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_object.h"
43 #include "got_lib_object_idset.h"
44 #include "got_lib_object_cache.h"
45 #include "got_lib_deflate.h"
46 #include "got_lib_pack.h"
47 #include "got_lib_privsep.h"
48 #include "got_lib_repository.h"
49 
50 #ifndef MAX
51 #define	MAX(_a,_b) ((_a) > (_b) ? (_a) : (_b))
52 #endif
53 
54 struct got_pack_meta {
55 	struct got_object_id id;
56 	char	*path;
57 	int	obj_type;
58 	time_t	mtime;
59 
60 	/* The best delta we picked */
61 	struct got_pack_meta *head;
62 	struct got_pack_meta *prev;
63 	struct got_delta_instruction *deltas;
64 	int	ndeltas;
65 	int	nchain;
66 
67 	/* Only used for delta window */
68 	struct got_delta_table *dtab;
69 
70 	/* Only used for writing offset deltas */
71 	off_t	off;
72 };
73 
74 struct got_pack_metavec {
75 	struct got_pack_meta **meta;
76 	int nmeta;
77 	int metasz;
78 };
79 
80 static const struct got_error *
81 alloc_meta(struct got_pack_meta **new, struct got_object_id *id,
82     const char *path, int obj_type, time_t mtime)
83 {
84 	const struct got_error *err = NULL;
85 	struct got_pack_meta *m;
86 
87 	*new = NULL;
88 
89 	m = calloc(1, sizeof(*m));
90 	if (m == NULL)
91 		return got_error_from_errno("calloc");
92 
93 	memcpy(&m->id, id, sizeof(m->id));
94 
95 	m->path = strdup(path);
96 	if (m->path == NULL) {
97 		err = got_error_from_errno("strdup");
98 		free(m);
99 		return err;
100 	}
101 
102 	m->obj_type = obj_type;
103 	m->mtime = mtime;
104 	*new = m;
105 	return NULL;
106 }
107 
108 static void
109 clear_meta(struct got_pack_meta *meta)
110 {
111 	if (meta == NULL)
112 		return;
113 	free(meta->deltas);
114 	meta->deltas = NULL;
115 	free(meta->path);
116 	meta->path = NULL;
117 }
118 
119 static void
120 free_nmeta(struct got_pack_meta **meta, int nmeta)
121 {
122 	int i;
123 
124 	for (i = 0; i < nmeta; i++)
125 		clear_meta(meta[i]);
126 	free(meta);
127 }
128 
129 static int
130 delta_order_cmp(const void *pa, const void *pb)
131 {
132 	struct got_pack_meta *a, *b;
133 	int cmp;
134 
135 	a = *(struct got_pack_meta **)pa;
136 	b = *(struct got_pack_meta **)pb;
137 
138 	if (a->obj_type != b->obj_type)
139 		return a->obj_type - b->obj_type;
140 	cmp = strcmp(a->path, b->path);
141 	if (cmp != 0)
142 		return cmp;
143 	if (a->mtime != b->mtime)
144 		return a->mtime - b->mtime;
145 	return got_object_id_cmp(&a->id, &b->id);
146 }
147 
148 static int
149 delta_size(struct got_delta_instruction *deltas, int ndeltas)
150 {
151 	int i, size = 32;
152 	for (i = 0; i < ndeltas; i++) {
153 		if (deltas[i].copy)
154 			size += GOT_DELTA_SIZE_SHIFT;
155 		else
156 			size += deltas[i].len + 1;
157 	}
158 	return size;
159 }
160 
161 
162 static const struct got_error *
163 pick_deltas(struct got_pack_meta **meta, int nmeta, int nours,
164     struct got_repository *repo,
165     got_pack_progress_cb progress_cb, void *progress_arg,
166     got_cancel_cb cancel_cb, void *cancel_arg)
167 {
168 	const struct got_error *err = NULL;
169 	struct got_pack_meta *m = NULL, *base = NULL;
170 	struct got_raw_object *raw = NULL, *base_raw = NULL;
171 	struct got_delta_instruction *deltas;
172 	int i, j, size, ndeltas, best;
173 	const int max_base_candidates = 10;
174 
175 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), delta_order_cmp);
176 	for (i = 0; i < nmeta; i++) {
177 		if (cancel_cb) {
178 			err = (*cancel_cb)(cancel_arg);
179 			if (err)
180 				break;
181 		}
182 		if (progress_cb) {
183 			err = progress_cb(progress_arg, 0L, nours, nmeta, i, 0);
184 			if (err)
185 				goto done;
186 		}
187 		m = meta[i];
188 		m->deltas = NULL;
189 		m->ndeltas = 0;
190 
191 		if (m->obj_type == GOT_OBJ_TYPE_COMMIT ||
192 		    m->obj_type == GOT_OBJ_TYPE_TAG)
193 			continue;
194 
195 		err = got_object_raw_open(&raw, repo, &m->id, 8192);
196 		if (err)
197 			goto done;
198 
199 		err = got_deltify_init(&m->dtab, raw->f, raw->hdrlen,
200 		    raw->size + raw->hdrlen);
201 		if (err)
202 			goto done;
203 
204 		if (i > max_base_candidates) {
205 			struct got_pack_meta *n = NULL;
206 			n = meta[i - (max_base_candidates + 1)];
207 			got_deltify_free(n->dtab);
208 			n->dtab = NULL;
209 		}
210 
211 		best = raw->size;
212 		for (j = MAX(0, i - max_base_candidates); j < i; j++) {
213 			if (cancel_cb) {
214 				err = (*cancel_cb)(cancel_arg);
215 				if (err)
216 					goto done;
217 			}
218 			base = meta[j];
219 			/* long chains make unpacking slow, avoid such bases */
220 			if (base->nchain >= 128 ||
221 			    base->obj_type != m->obj_type)
222 				continue;
223 
224 			err = got_object_raw_open(&base_raw, repo, &base->id,
225 			    8192);
226 			if (err)
227 				goto done;
228 			err = got_deltify(&deltas, &ndeltas,
229 			    raw->f, raw->hdrlen, raw->size + raw->hdrlen,
230 			    base->dtab, base_raw->f, base_raw->hdrlen,
231 			    base_raw->size + base_raw->hdrlen);
232 			got_object_raw_close(base_raw);
233 			base_raw = NULL;
234 			if (err)
235 				goto done;
236 
237 			size = delta_size(deltas, ndeltas);
238 			if (size + 32 < best){
239 				/*
240 				 * if we already picked a best delta,
241 				 * replace it.
242 				 */
243 				free(m->deltas);
244 				best = size;
245 				m->deltas = deltas;
246 				m->ndeltas = ndeltas;
247 				m->nchain = base->nchain + 1;
248 				m->prev = base;
249 				m->head = base->head;
250 				if (m->head == NULL)
251 					m->head = base;
252 			} else {
253 				free(deltas);
254 				deltas = NULL;
255 				ndeltas = 0;
256 			}
257 		}
258 
259 		got_object_raw_close(raw);
260 		raw = NULL;
261 	}
262 done:
263 	for (i = MAX(0, nmeta - max_base_candidates); i < nmeta; i++) {
264 		got_deltify_free(meta[i]->dtab);
265 		meta[i]->dtab = NULL;
266 	}
267 	if (raw)
268 		got_object_raw_close(raw);
269 	if (base_raw)
270 		got_object_raw_close(base_raw);
271 	return err;
272 }
273 
274 static const struct got_error *
275 search_packidx(int *found, struct got_object_id *id,
276     struct got_repository *repo)
277 {
278 	const struct got_error *err = NULL;
279 	struct got_packidx *packidx = NULL;
280 	int idx;
281 
282 	*found = 0;
283 
284 	err = got_repo_search_packidx(&packidx, &idx, repo, id);
285 	if (err == NULL)
286 		*found = 1; /* object is already packed */
287 	else if (err->code == GOT_ERR_NO_OBJ)
288 		err = NULL;
289 	return err;
290 }
291 
292 static const int obj_types[] = {
293 	GOT_OBJ_TYPE_ANY,
294 	GOT_OBJ_TYPE_COMMIT,
295 	GOT_OBJ_TYPE_TREE,
296 	GOT_OBJ_TYPE_BLOB,
297 	GOT_OBJ_TYPE_TAG,
298 	GOT_OBJ_TYPE_OFFSET_DELTA,
299 	GOT_OBJ_TYPE_REF_DELTA
300 };
301 
302 static const struct got_error *
303 add_meta(struct got_pack_metavec *v, struct got_object_idset *idset,
304     struct got_object_id *id, const char *path, int obj_type,
305     time_t mtime, int loose_obj_only, struct got_repository *repo)
306 {
307 	const struct got_error *err;
308 	struct got_pack_meta *m;
309 
310 	if (loose_obj_only) {
311 		int is_packed;
312 		err = search_packidx(&is_packed, id, repo);
313 		if (err)
314 			return err;
315 		if (is_packed)
316 			return NULL;
317 	}
318 
319 	err = got_object_idset_add(idset, id, (void *)&obj_types[obj_type]);
320 	if (err)
321 		return err;
322 
323 	if (v == NULL)
324 		return NULL;
325 
326 	err = alloc_meta(&m, id, path, obj_type, mtime);
327 	if (err)
328 		goto done;
329 
330 	if (v->nmeta == v->metasz){
331 		size_t newsize = 2 * v->metasz;
332 		struct got_pack_meta **new;
333 		new = reallocarray(v->meta, newsize, sizeof(*new));
334 		if (new == NULL) {
335 			err = got_error_from_errno("reallocarray");
336 			goto done;
337 		}
338 		v->meta = new;
339 		v->metasz = newsize; 
340 	}
341 done:
342 	if (err) {
343 		clear_meta(m);
344 		free(m);
345 	} else
346 		v->meta[v->nmeta++] = m;
347 
348 	return err;
349 }
350 
351 static const struct got_error *
352 load_tree_entries(struct got_object_id_queue *ids, struct got_pack_metavec *v,
353     struct got_object_idset *idset, struct got_object_id *tree_id,
354     const char *dpath, time_t mtime, struct got_repository *repo,
355     int loose_obj_only, got_cancel_cb cancel_cb, void *cancel_arg)
356 {
357 	const struct got_error *err;
358 	struct got_tree_object *tree;
359 	char *p = NULL;
360 	int i;
361 
362 	err = got_object_open_as_tree(&tree, repo, tree_id);
363 	if (err)
364 		return err;
365 
366 	for (i = 0; i < got_object_tree_get_nentries(tree); i++) {
367 		struct got_tree_entry *e = got_object_tree_get_entry(tree, i);
368 		struct got_object_id *id = got_tree_entry_get_id(e);
369 		mode_t mode = got_tree_entry_get_mode(e);
370 
371 		if (cancel_cb) {
372 			err = (*cancel_cb)(cancel_arg);
373 			if (err)
374 				break;
375 		}
376 
377 		if (got_object_tree_entry_is_submodule(e) ||
378 		    got_object_idset_contains(idset, id))
379 			continue;
380 		
381 		if (asprintf(&p, "%s%s%s", dpath, dpath[0] != '\0' ? "/" : "",
382 		    got_tree_entry_get_name(e)) == -1) {
383 			err = got_error_from_errno("asprintf");
384 			break;
385 		}
386 
387 		if (S_ISDIR(mode)) {
388 			struct got_object_qid *qid;
389 			err = got_object_qid_alloc(&qid, id);
390 			if (err)
391 				break;
392 			STAILQ_INSERT_TAIL(ids, qid, entry);
393 		} else if (S_ISREG(mode) || S_ISLNK(mode)) {
394 			err = add_meta(v, idset, id, p, GOT_OBJ_TYPE_BLOB,
395 			    mtime, loose_obj_only, repo);
396 			if (err)
397 				break;
398 		}
399 		free(p);
400 		p = NULL;
401 	}
402 
403 	got_object_tree_close(tree);
404 	free(p);
405 	return err;
406 }
407 
408 static const struct got_error *
409 load_tree(struct got_pack_metavec *v, struct got_object_idset *idset,
410     struct got_object_id *tree_id, const char *dpath, time_t mtime,
411     int loose_obj_only, struct got_repository *repo,
412     got_cancel_cb cancel_cb, void *cancel_arg)
413 {
414 	const struct got_error *err = NULL;
415 	struct got_object_id_queue tree_ids;
416 	struct got_object_qid *qid;
417 
418 	if (got_object_idset_contains(idset, tree_id))
419 		return NULL;
420 
421 	err = got_object_qid_alloc(&qid, tree_id);
422 	if (err)
423 		return err;
424 
425 	STAILQ_INIT(&tree_ids);
426 	STAILQ_INSERT_TAIL(&tree_ids, qid, entry);
427 
428 	while (!STAILQ_EMPTY(&tree_ids)) {
429 		if (cancel_cb) {
430 			err = (*cancel_cb)(cancel_arg);
431 			if (err)
432 				break;
433 		}
434 
435 		qid = STAILQ_FIRST(&tree_ids);
436 		STAILQ_REMOVE_HEAD(&tree_ids, entry);
437 
438 		if (got_object_idset_contains(idset, qid->id)) {
439 			got_object_qid_free(qid);
440 			continue;
441 		}
442 
443 		err = add_meta(v, idset, qid->id, dpath, GOT_OBJ_TYPE_TREE,
444 		    mtime, loose_obj_only, repo);
445 		if (err) {
446 			got_object_qid_free(qid);
447 			break;
448 		}
449 
450 		err = load_tree_entries(&tree_ids, v, idset, qid->id, dpath,
451 		    mtime, repo, loose_obj_only, cancel_cb, cancel_arg);
452 		got_object_qid_free(qid);
453 		if (err)
454 			break;
455 	}
456 
457 	got_object_id_queue_free(&tree_ids);
458 	return err;
459 }
460 
461 static const struct got_error *
462 load_commit(struct got_pack_metavec *v, struct got_object_idset *idset,
463     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
464     got_cancel_cb cancel_cb, void *cancel_arg)
465 {
466 	const struct got_error *err;
467 	struct got_commit_object *commit;
468 
469 	if (got_object_idset_contains(idset, id))
470 		return NULL;
471 
472 	if (loose_obj_only) {
473 		int is_packed;
474 		err = search_packidx(&is_packed, id, repo);
475 		if (err)
476 			return err;
477 		if (is_packed)
478 			return NULL;
479 	}
480 
481 	err = got_object_open_as_commit(&commit, repo, id);
482 	if (err)
483 		return err;
484 
485 	err = add_meta(v, idset, id, "", GOT_OBJ_TYPE_COMMIT,
486 	    got_object_commit_get_committer_time(commit),
487 	    loose_obj_only, repo);
488 	if (err)
489 		goto done;
490 
491 	err = load_tree(v, idset, got_object_commit_get_tree_id(commit),
492 	    "", got_object_commit_get_committer_time(commit),
493 	    loose_obj_only, repo, cancel_cb, cancel_arg);
494 done:
495 	got_object_commit_close(commit);
496 	return err;
497 }
498 
499 static const struct got_error *
500 load_tag(struct got_pack_metavec *v, struct got_object_idset *idset,
501     struct got_object_id *id, struct got_repository *repo, int loose_obj_only,
502     got_cancel_cb cancel_cb, void *cancel_arg)
503 {
504 	const struct got_error *err;
505 	struct got_tag_object *tag = NULL;
506 
507 	if (got_object_idset_contains(idset, id))
508 		return NULL;
509 
510 	if (loose_obj_only) {
511 		int is_packed;
512 		err = search_packidx(&is_packed, id, repo);
513 		if (err)
514 			return err;
515 		if (is_packed)
516 			return NULL;
517 	}
518 
519 	err = got_object_open_as_tag(&tag, repo, id);
520 	if (err)
521 		return err;
522 
523 	err = add_meta(v, idset, id, "", GOT_OBJ_TYPE_TAG,
524 	    got_object_tag_get_tagger_time(tag),
525 	    loose_obj_only, repo);
526 	if (err)
527 		goto done;
528 
529 	switch (got_object_tag_get_object_type(tag)) {
530 	case GOT_OBJ_TYPE_COMMIT:
531 		err = load_commit(v, idset,
532 		    got_object_tag_get_object_id(tag), repo,
533 		    loose_obj_only, cancel_cb, cancel_arg);
534 		break;
535 	case GOT_OBJ_TYPE_TREE:
536 		err = load_tree(v, idset, got_object_tag_get_object_id(tag),
537 		    "", got_object_tag_get_tagger_time(tag),
538 		    loose_obj_only, repo, cancel_cb, cancel_arg);
539 		break;
540 	default:
541 		break;
542 	}
543 
544 done:
545 	got_object_tag_close(tag);
546 	return err;
547 }
548 
549 enum findtwixt_color {
550 	COLOR_KEEP = 0,
551 	COLOR_DROP,
552 	COLOR_BLANK,
553 };
554 static const int findtwixt_colors[] = {
555 	COLOR_KEEP,
556 	COLOR_DROP,
557 	COLOR_BLANK
558 };
559 
560 static const struct got_error *
561 queue_commit_id(struct got_object_id_queue *ids, struct got_object_id *id,
562     int color, struct got_repository *repo)
563 {
564 	const struct got_error *err;
565 	struct got_object_qid *qid;
566 
567 	err = got_object_qid_alloc(&qid, id);
568 	if (err)
569 		return err;
570 
571 	STAILQ_INSERT_TAIL(ids, qid, entry);
572 	qid->data = (void *)&findtwixt_colors[color];
573 	return NULL;
574 }
575 
576 static const struct got_error *
577 drop_commit(struct got_object_idset *keep, struct got_object_idset *drop,
578     struct got_object_id *id, struct got_repository *repo,
579     got_cancel_cb cancel_cb, void *cancel_arg)
580 {
581 	const struct got_error *err = NULL;
582 	struct got_commit_object *commit;
583 	const struct got_object_id_queue *parents;
584 	struct got_object_id_queue ids;
585 	struct got_object_qid *qid;
586 
587 	STAILQ_INIT(&ids);
588 
589 	err = got_object_qid_alloc(&qid, id);
590 	if (err)
591 		return err;
592 	STAILQ_INSERT_HEAD(&ids, qid, entry);
593 
594 	while (!STAILQ_EMPTY(&ids)) {
595 		if (cancel_cb) {
596 			err = (*cancel_cb)(cancel_arg);
597 			if (err)
598 				break;
599 		}
600 
601 		qid = STAILQ_FIRST(&ids);
602 		STAILQ_REMOVE_HEAD(&ids, entry);
603 
604 		if (got_object_idset_contains(drop, qid->id)) {
605 			got_object_qid_free(qid);
606 			continue;
607 		}
608 
609 		err = got_object_idset_add(drop, qid->id,
610 		    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
611 		if (err) {
612 			got_object_qid_free(qid);
613 			break;
614 		}
615 
616 		if (!got_object_idset_contains(keep, qid->id)) {
617 			got_object_qid_free(qid);
618 			continue;
619 		}
620 
621 		err = got_object_open_as_commit(&commit, repo, qid->id);
622 		got_object_qid_free(qid);
623 		if (err)
624 			break;
625 
626 		parents = got_object_commit_get_parent_ids(commit);
627 		if (parents) {
628 			err = got_object_id_queue_copy(parents, &ids);
629 			if (err) {
630 				got_object_commit_close(commit);
631 				break;
632 			}
633 		}
634 		got_object_commit_close(commit);
635 	}
636 
637 	got_object_id_queue_free(&ids);
638 	return err;
639 }
640 
641 struct append_id_arg {
642 	struct got_object_id **array;
643 	int idx;
644 };
645 
646 static const struct got_error *
647 append_id(struct got_object_id *id, void *data, void *arg)
648 {
649 	struct append_id_arg *a = arg;
650 
651 	a->array[a->idx] = got_object_id_dup(id);
652 	if (a->array[a->idx] == NULL)
653 		return got_error_from_errno("got_object_id_dup");
654 
655 	a->idx++;
656 	return NULL;
657 }
658 
659 static const struct got_error *
660 findtwixt(struct got_object_id ***res, int *nres,
661     struct got_object_id **head, int nhead,
662     struct got_object_id **tail, int ntail,
663     struct got_repository *repo,
664     got_cancel_cb cancel_cb, void *cancel_arg)
665 {
666 	const struct got_error *err = NULL;
667 	struct got_object_id_queue ids;
668 	struct got_object_idset *keep, *drop;
669 	struct got_object_qid *qid;
670 	int i, ncolor, nkeep, obj_type;
671 
672 	STAILQ_INIT(&ids);
673 	*res = NULL;
674 	*nres = 0;
675 
676 	keep = got_object_idset_alloc();
677 	if (keep == NULL)
678 		return got_error_from_errno("got_object_idset_alloc");
679 
680 	drop = got_object_idset_alloc();
681 	if (drop == NULL) {
682 		err = got_error_from_errno("got_object_idset_alloc");
683 		goto done;
684 	}
685 
686 	for (i = 0; i < nhead; i++) {
687 		struct got_object_id *id = head[i];
688 		if (id == NULL)
689 			continue;
690 		err = got_object_get_type(&obj_type, repo, id);
691 		if (err)
692 			return err;
693 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
694 			continue;
695 		err = queue_commit_id(&ids, id, COLOR_KEEP, repo);
696 		if (err)
697 			goto done;
698 	}		
699 	for (i = 0; i < ntail; i++) {
700 		struct got_object_id *id = tail[i];
701 		if (id == NULL)
702 			continue;
703 		err = got_object_get_type(&obj_type, repo, id);
704 		if (err)
705 			return err;
706 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
707 			continue;
708 		err = queue_commit_id(&ids, id, COLOR_DROP, repo);
709 		if (err)
710 			goto done;
711 	}
712 
713 	while (!STAILQ_EMPTY(&ids)) {
714 		int qcolor;
715 		qid = STAILQ_FIRST(&ids);
716 		qcolor = *((int *)qid->data);
717 
718 		if (got_object_idset_contains(drop, qid->id))
719 			ncolor = COLOR_DROP;
720 		else if (got_object_idset_contains(keep, qid->id))
721 			ncolor = COLOR_KEEP;
722 		else
723 			ncolor = COLOR_BLANK;
724 
725 		if (ncolor == COLOR_DROP || (ncolor == COLOR_KEEP &&
726 		    qcolor == COLOR_KEEP)) {
727 			STAILQ_REMOVE_HEAD(&ids, entry);
728 			got_object_qid_free(qid);
729 			continue;
730 		}
731 
732 		if (ncolor == COLOR_KEEP && qcolor == COLOR_DROP) {
733 			err = drop_commit(keep, drop, qid->id, repo,
734 			    cancel_cb, cancel_arg);
735 			if (err)
736 				goto done;
737 		} else if (ncolor == COLOR_BLANK) {
738 			struct got_commit_object *commit;
739 			struct got_object_id *id;
740 			const struct got_object_id_queue *parents;
741 			struct got_object_qid *pid;
742 
743 			id = got_object_id_dup(qid->id);
744 			if (id == NULL) {
745 				err = got_error_from_errno("got_object_id_dup");
746 				goto done;
747 			}
748 			if (qcolor == COLOR_KEEP)
749 				err = got_object_idset_add(keep, id,
750 				    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
751 			else
752 				err = got_object_idset_add(drop, id,
753 				    (void *)&obj_types[GOT_OBJ_TYPE_COMMIT]);
754 			if (err) {
755 				free(id);
756 				goto done;
757 			}
758 
759 			err = got_object_open_as_commit(&commit, repo, id);
760 			if (err) {
761 				free(id);
762 				goto done;
763 			}
764 			parents = got_object_commit_get_parent_ids(commit);
765 			if (parents) {
766 				STAILQ_FOREACH(pid, parents, entry) {
767 					err = queue_commit_id(&ids, pid->id,
768 					    qcolor, repo);
769 					if (err) {
770 						free(id);
771 						goto done;
772 					}
773 				}
774 			}
775 			got_object_commit_close(commit);
776 			commit = NULL;
777 		} else {
778 			/* should not happen */
779 			err = got_error_fmt(GOT_ERR_NOT_IMPL,
780 			    "%s ncolor=%d qcolor=%d", __func__, ncolor, qcolor);
781 			goto done;
782 		}
783 
784 		STAILQ_REMOVE_HEAD(&ids, entry);
785 		got_object_qid_free(qid);
786 	}
787 
788 	nkeep = got_object_idset_num_elements(keep);
789 	if (nkeep > 0) {
790 		struct append_id_arg arg;
791 		arg.array = calloc(nkeep, sizeof(struct got_object_id *));
792 		if (arg.array == NULL) {
793 			err = got_error_from_errno("calloc");
794 			goto done;
795 		}
796 		arg.idx = 0;
797 		err = got_object_idset_for_each(keep, append_id, &arg);
798 		if (err) {
799 			free(arg.array);
800 			goto done;
801 		}
802 		*res = arg.array;
803 		*nres = nkeep;
804 	}
805 done:
806 	got_object_idset_free(keep);
807 	got_object_idset_free(drop);
808 	got_object_id_queue_free(&ids);
809 	return err;
810 }
811 
812 static const struct got_error *
813 read_meta(struct got_pack_meta ***meta, int *nmeta,
814     struct got_object_id **theirs, int ntheirs,
815     struct got_object_id **ours, int nours, struct got_repository *repo,
816     int loose_obj_only, got_pack_progress_cb progress_cb, void *progress_arg,
817     got_cancel_cb cancel_cb, void *cancel_arg)
818 {
819 	const struct got_error *err = NULL;
820 	struct got_object_id **ids = NULL;
821 	struct got_object_idset *idset;
822 	int i, nobj = 0, obj_type;
823 	struct got_pack_metavec v;
824 
825 	*meta = NULL;
826 	*nmeta = 0;
827 
828 	idset = got_object_idset_alloc();
829 	if (idset == NULL)
830 		return got_error_from_errno("got_object_idset_alloc");
831 
832 	v.nmeta = 0;
833 	v.metasz = 64;
834 	v.meta = calloc(v.metasz, sizeof(struct got_pack_meta *));
835 	if (v.meta == NULL) {
836 		err = got_error_from_errno("calloc");
837 		goto done;
838 	}
839 
840 	err = findtwixt(&ids, &nobj, ours, nours, theirs, ntheirs, repo,
841 	    cancel_cb, cancel_arg);
842 	if (err || nobj == 0)
843 		goto done;
844 
845 	for (i = 0; i < ntheirs; i++) {
846 		struct got_object_id *id = theirs[i];
847 		if (id == NULL)
848 			continue;
849 		err = got_object_get_type(&obj_type, repo, id);
850 		if (err)
851 			return err;
852 		if (obj_type != GOT_OBJ_TYPE_COMMIT)
853 			continue;
854 		err = load_commit(NULL, idset, id, repo,
855 		    loose_obj_only, cancel_cb, cancel_arg);
856 		if (err)
857 			goto done;
858 		if (progress_cb) {
859 			err = progress_cb(progress_arg, 0L, nours,
860 			    v.nmeta, 0, 0);
861 			if (err)
862 				goto done;
863 		}
864 	}
865 
866 	for (i = 0; i < ntheirs; i++) {
867 		struct got_object_id *id = theirs[i];
868 		int *cached_type;
869 		if (id == NULL)
870 			continue;
871 		cached_type = got_object_idset_get(idset, id);
872 		if (cached_type == NULL) {
873 			err = got_object_get_type(&obj_type, repo, id);
874 			if (err)
875 				goto done;
876 		} else
877 			obj_type = *cached_type;
878 		if (obj_type != GOT_OBJ_TYPE_TAG)
879 			continue;
880 		err = load_tag(NULL, idset, id, repo,
881 		    loose_obj_only, cancel_cb, cancel_arg);
882 		if (err)
883 			goto done;
884 		if (progress_cb) {
885 			err = progress_cb(progress_arg, 0L, nours,
886 			    v.nmeta, 0, 0);
887 			if (err)
888 				goto done;
889 		}
890 	}
891 
892 	for (i = 0; i < nobj; i++) {
893 		err = load_commit(&v, idset, ids[i], repo,
894 		    loose_obj_only, cancel_cb, cancel_arg);
895 		if (err)
896 			goto done;
897 		if (progress_cb) {
898 			err = progress_cb(progress_arg, 0L, nours,
899 			    v.nmeta, 0, 0);
900 			if (err)
901 				goto done;
902 		}
903 	}
904 
905 	for (i = 0; i < nours; i++) {
906 		struct got_object_id *id = ours[i];
907 		int *cached_type;
908 		if (id == NULL)
909 			continue;
910 		cached_type = got_object_idset_get(idset, id);
911 		if (cached_type == NULL) {
912 			err = got_object_get_type(&obj_type, repo, id);
913 			if (err)
914 				goto done;
915 		} else
916 			obj_type = *cached_type;
917 		if (obj_type != GOT_OBJ_TYPE_TAG)
918 			continue;
919 		err = load_tag(&v, idset, id, repo,
920 		    loose_obj_only, cancel_cb, cancel_arg);
921 		if (err)
922 			goto done;
923 		if (progress_cb) {
924 			err = progress_cb(progress_arg, 0L, nours,
925 			    v.nmeta, 0, 0);
926 			if (err)
927 				goto done;
928 		}
929 	}
930 
931 done:
932 	for (i = 0; i < nobj; i++) {
933 		free(ids[i]);
934 	}
935 	free(ids);
936 	got_object_idset_free(idset);
937 	if (err == NULL) {
938 		*meta = v.meta;
939 		*nmeta = v.nmeta;
940 	} else
941 		free(v.meta);
942 
943 	return err;
944 }
945 
946 const struct got_error *
947 hwrite(FILE *f, void *buf, int len, SHA1_CTX *ctx)
948 {
949 	size_t n;
950 
951 	SHA1Update(ctx, buf, len);
952 	n = fwrite(buf, 1, len, f);
953 	if (n != len)
954 		return got_ferror(f, GOT_ERR_IO);
955 	return NULL;
956 }
957 
958 static void
959 putbe32(char *b, uint32_t n)
960 {
961 	b[0] = n >> 24;
962 	b[1] = n >> 16;
963 	b[2] = n >> 8;
964 	b[3] = n >> 0;
965 }
966 
967 static int
968 write_order_cmp(const void *pa, const void *pb)
969 {
970 	struct got_pack_meta *a, *b, *ahd, *bhd;
971 
972 	a = *(struct got_pack_meta **)pa;
973 	b = *(struct got_pack_meta **)pb;
974 	ahd = (a->head == NULL) ? a : a->head;
975 	bhd = (b->head == NULL) ? b : b->head;
976 	if (ahd->mtime != bhd->mtime)
977 		return bhd->mtime - ahd->mtime;
978 	if (ahd != bhd)
979 		return (uintptr_t)bhd - (uintptr_t)ahd;
980 	if (a->nchain != b->nchain)
981 		return a->nchain - b->nchain;
982 	return a->mtime - b->mtime;
983 }
984 
985 static const struct got_error *
986 packhdr(int *hdrlen, char *hdr, size_t bufsize, int obj_type, size_t len)
987 {
988 	size_t i;
989 
990 	*hdrlen = 0;
991 
992 	hdr[0] = obj_type << 4;
993 	hdr[0] |= len & 0xf;
994 	len >>= 4;
995 	for (i = 1; len != 0; i++){
996 		if (i >= bufsize)
997 			return got_error(GOT_ERR_NO_SPACE);
998 		hdr[i - 1] |= GOT_DELTA_SIZE_MORE;
999 		hdr[i] = len & GOT_DELTA_SIZE_VAL_MASK;
1000 		len >>= GOT_DELTA_SIZE_SHIFT;
1001 	}
1002 
1003 	*hdrlen = i;
1004 	return NULL;
1005 }
1006 
1007 static const struct got_error *
1008 append(char **p, int *len, int *sz, void *seg, int nseg)
1009 {
1010 	char *n;
1011 
1012 	if (*len + nseg >= *sz) {
1013 		while (*len + nseg >= *sz)
1014 			*sz += *sz / 2;
1015 		n = realloc(*p, *sz);
1016 		if (n == NULL)
1017 			return got_error_from_errno("realloc");
1018 		*p = n;
1019 	}
1020 	memcpy(*p + *len, seg, nseg);
1021 	*len += nseg;
1022 	return NULL;
1023 }
1024 
1025 
1026 static const struct got_error *
1027 encodedelta(int *nd, struct got_pack_meta *m, struct got_raw_object *o,
1028     off_t base_size, char **pp)
1029 {
1030 	const struct got_error *err = NULL;
1031 	char *p;
1032 	unsigned char buf[16], *bp;
1033 	int len, sz, i, j;
1034 	off_t n;
1035 	struct got_delta_instruction *d;
1036 
1037 	*pp = NULL;
1038 	*nd = 0;
1039 
1040 	sz = 128;
1041 	len = 0;
1042 	p = malloc(sz);
1043 	if (p == NULL)
1044 		return got_error_from_errno("malloc");
1045 
1046 	/* base object size */
1047 	buf[0] = base_size & GOT_DELTA_SIZE_VAL_MASK;
1048 	n = base_size >> GOT_DELTA_SIZE_SHIFT;
1049 	for (i = 1; n > 0; i++) {
1050 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
1051 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
1052 		n >>= GOT_DELTA_SIZE_SHIFT;
1053 	}
1054 	err = append(&p, &len, &sz, buf, i);
1055 	if (err)
1056 		return err;
1057 
1058 	/* target object size */
1059 	buf[0] = o->size & GOT_DELTA_SIZE_VAL_MASK;
1060 	n = o->size >> GOT_DELTA_SIZE_SHIFT;
1061 	for (i = 1; n > 0; i++) {
1062 		buf[i - 1] |= GOT_DELTA_SIZE_MORE;
1063 		buf[i] = n & GOT_DELTA_SIZE_VAL_MASK;
1064 		n >>= GOT_DELTA_SIZE_SHIFT;
1065 	}
1066 	err = append(&p, &len, &sz, buf, i);
1067 	if (err)
1068 		return err;
1069 	for (j = 0; j < m->ndeltas; j++) {
1070 		d = &m->deltas[j];
1071 		if (d->copy) {
1072 			n = d->offset;
1073 			bp = &buf[1];
1074 			buf[0] = GOT_DELTA_BASE_COPY;
1075 			for (i = 0; i < 4; i++) {
1076 				/* DELTA_COPY_OFF1 ... DELTA_COPY_OFF4 */
1077 				buf[0] |= 1 << i;
1078 				*bp++ = n & 0xff;
1079 				n >>= 8;
1080 				if (n == 0)
1081 					break;
1082 			}
1083 
1084 			n = d->len;
1085 			if (n != GOT_DELTA_COPY_DEFAULT_LEN) {
1086 				/* DELTA_COPY_LEN1 ... DELTA_COPY_LEN3 */
1087 				for (i = 0; i < 3 && n > 0; i++) {
1088 					buf[0] |= 1 << (i + 4);
1089 					*bp++ = n & 0xff;
1090 					n >>= 8;
1091 				}
1092 			}
1093 			err = append(&p, &len, &sz, buf, bp - buf);
1094 			if (err)
1095 				return err;
1096 		} else {
1097 			char content[128];
1098 			size_t r;
1099 			if (fseeko(o->f, o->hdrlen + d->offset, SEEK_SET) == -1)
1100 				return got_error_from_errno("fseeko");
1101 			n = 0;
1102 			while (n != d->len) {
1103 				buf[0] = (d->len - n < 127) ? d->len - n : 127;
1104 				err = append(&p, &len, &sz, buf, 1);
1105 				if (err)
1106 					return err;
1107 				r = fread(content, 1, buf[0], o->f);
1108 				if (r != buf[0])
1109 					return got_ferror(o->f, GOT_ERR_IO);
1110 				err = append(&p, &len, &sz, content, buf[0]);
1111 				if (err)
1112 					return err;
1113 				n += buf[0];
1114 			}
1115 		}
1116 	}
1117 	*pp = p;
1118 	*nd = len;
1119 	return NULL;
1120 }
1121 
1122 static int
1123 packoff(char *hdr, off_t off)
1124 {
1125 	int i, j;
1126 	char rbuf[8];
1127 
1128 	rbuf[0] = off & GOT_DELTA_SIZE_VAL_MASK;
1129 	for (i = 1; (off >>= GOT_DELTA_SIZE_SHIFT) != 0; i++) {
1130 		rbuf[i] = (--off & GOT_DELTA_SIZE_VAL_MASK) |
1131 		    GOT_DELTA_SIZE_MORE;
1132 	}
1133 
1134 	j = 0;
1135 	while (i > 0)
1136 		hdr[j++] = rbuf[--i];
1137 	return j;
1138 }
1139 
1140 static const struct got_error *
1141 genpack(uint8_t *pack_sha1, FILE *packfile,
1142     struct got_pack_meta **meta, int nmeta, int nours,
1143     int use_offset_deltas, struct got_repository *repo,
1144     got_pack_progress_cb progress_cb, void *progress_arg,
1145     got_cancel_cb cancel_cb, void *cancel_arg)
1146 {
1147 	const struct got_error *err = NULL;
1148 	int i, nh, nd;
1149 	SHA1_CTX ctx;
1150 	struct got_pack_meta *m;
1151 	struct got_raw_object *raw;
1152 	char *p = NULL, buf[32];
1153 	size_t outlen, n;
1154 	struct got_deflate_checksum csum;
1155 	off_t packfile_size = 0;
1156 
1157 	SHA1Init(&ctx);
1158 	csum.output_sha1 = &ctx;
1159 	csum.output_crc = NULL;
1160 
1161 	err = hwrite(packfile, "PACK", 4, &ctx);
1162 	if (err)
1163 		return err;
1164 	putbe32(buf, GOT_PACKFILE_VERSION);
1165 	err = hwrite(packfile, buf, 4, &ctx);
1166 	if (err)
1167 		goto done;
1168 	putbe32(buf, nmeta);
1169 	err = hwrite(packfile, buf, 4, &ctx);
1170 	if (err)
1171 		goto done;
1172 	qsort(meta, nmeta, sizeof(struct got_pack_meta *), write_order_cmp);
1173 	for (i = 0; i < nmeta; i++) {
1174 		if (progress_cb) {
1175 			err = progress_cb(progress_arg, packfile_size, nours,
1176 			    nmeta, nmeta, i);
1177 			if (err)
1178 				goto done;
1179 		}
1180 		m = meta[i];
1181 		m->off = ftello(packfile);
1182 		err = got_object_raw_open(&raw, repo, &m->id, 8192);
1183 		if (err)
1184 			goto done;
1185 		if (m->deltas == NULL) {
1186 			err = packhdr(&nh, buf, sizeof(buf),
1187 			    m->obj_type, raw->size);
1188 			if (err)
1189 				goto done;
1190 			err = hwrite(packfile, buf, nh, &ctx);
1191 			if (err)
1192 				goto done;
1193 			packfile_size += nh;
1194 			if (fseeko(raw->f, raw->hdrlen, SEEK_SET) == -1) {
1195 				err = got_error_from_errno("fseeko");
1196 				goto done;
1197 			}
1198 			err = got_deflate_to_file(&outlen, raw->f, packfile,
1199 			    &csum);
1200 			if (err)
1201 				goto done;
1202 			packfile_size += outlen;
1203 		} else {
1204 			FILE *delta_file;
1205 			struct got_raw_object *base_raw;
1206 			err = got_object_raw_open(&base_raw, repo,
1207 			    &m->prev->id, 8192);
1208 			if (err)
1209 				goto done;
1210 			err = encodedelta(&nd, m, raw, base_raw->size, &p);
1211 			if (err)
1212 				goto done;
1213 			got_object_raw_close(base_raw);
1214 			if (use_offset_deltas && m->prev->off != 0) {
1215 				err = packhdr(&nh, buf, sizeof(buf),
1216 				    GOT_OBJ_TYPE_OFFSET_DELTA, nd);
1217 				if (err)
1218 					goto done;
1219 				nh += packoff(buf + nh,
1220 				    m->off - m->prev->off);
1221 				err = hwrite(packfile, buf, nh, &ctx);
1222 				if (err)
1223 					goto done;
1224 				packfile_size += nh;
1225 			} else {
1226 				err = packhdr(&nh, buf, sizeof(buf),
1227 				    GOT_OBJ_TYPE_REF_DELTA, nd);
1228 				err = hwrite(packfile, buf, nh, &ctx);
1229 				if (err)
1230 					goto done;
1231 				packfile_size += nh;
1232 				err = hwrite(packfile, m->prev->id.sha1,
1233 				    sizeof(m->prev->id.sha1), &ctx);
1234 				packfile_size += sizeof(m->prev->id.sha1);
1235 				if (err)
1236 					goto done;
1237 			}
1238 			/* XXX need got_deflate_from_mem() */
1239 			delta_file = fmemopen(p, nd, "r");
1240 			if (delta_file == NULL) {
1241 				err = got_error_from_errno("fmemopen");
1242 				goto done;
1243 			}
1244 			err = got_deflate_to_file(&outlen, delta_file,
1245 			    packfile, &csum);
1246 			fclose(delta_file);
1247 			if (err)
1248 				goto done;
1249 			packfile_size += outlen;
1250 			free(p);
1251 			p = NULL;
1252 		}
1253 		got_object_raw_close(raw);
1254 		raw = NULL;
1255 	}
1256 	SHA1Final(pack_sha1, &ctx);
1257 	n = fwrite(pack_sha1, 1, SHA1_DIGEST_LENGTH, packfile);
1258 	if (n != SHA1_DIGEST_LENGTH)
1259 		err = got_ferror(packfile, GOT_ERR_IO);
1260 	packfile_size += SHA1_DIGEST_LENGTH;
1261 	packfile_size += sizeof(struct got_packfile_hdr);
1262 	err = progress_cb(progress_arg, packfile_size, nours,
1263 	    nmeta, nmeta, nmeta);
1264 	if (err)
1265 		goto done;
1266 done:
1267 	free(p);
1268 	return err;
1269 }
1270 
1271 const struct got_error *
1272 got_pack_create(uint8_t *packsha1, FILE *packfile,
1273     struct got_object_id **theirs, int ntheirs,
1274     struct got_object_id **ours, int nours,
1275     struct got_repository *repo, int loose_obj_only, int allow_empty,
1276     got_pack_progress_cb progress_cb, void *progress_arg,
1277     got_cancel_cb cancel_cb, void *cancel_arg)
1278 {
1279 	const struct got_error *err;
1280 	struct got_pack_meta **meta;
1281 	int nmeta;
1282 
1283 	err = read_meta(&meta, &nmeta, theirs, ntheirs, ours, nours, repo,
1284 	    loose_obj_only, progress_cb, progress_arg, cancel_cb, cancel_arg);
1285 	if (err)
1286 		return err;
1287 
1288 	if (nmeta == 0 && !allow_empty) {
1289 		err = got_error(GOT_ERR_CANNOT_PACK);
1290 		goto done;
1291 	}
1292 	if (nmeta > 0) {
1293 		err = pick_deltas(meta, nmeta, nours, repo,
1294 		    progress_cb, progress_arg, cancel_cb, cancel_arg);
1295 		if (err)
1296 			goto done;
1297 	}
1298 
1299 	err = genpack(packsha1, packfile, meta, nmeta, nours, 1, repo,
1300 	    progress_cb, progress_arg, cancel_cb, cancel_arg);
1301 	if (err)
1302 		goto done;
1303 done:
1304 	free_nmeta(meta, nmeta);
1305 	return err;
1306 }